To confirm the laid position of a buried pipe with a simple device without giving any trouble to residents by changing the color of a temperature indicating material by warming or cooling the buried pipe after the temperature indicating material is stuck to the surface of concrete in which the buried pipe is laid.
An irreversible temperature indicating material is used as the temperature indicting material 1 to be stuck to the surface of concrete in which a buried pipe is laid. The material 1 is formed in a tape-like shape and can be stuck to the surface of the concrete by only stripping off the rear paper (parting paper) coated with a heat-resistant adhesive mass. The block allotting drawing of the concrete wall 3 of a reinforced concrete structure 2 is prepared and a grid-like indicating section 4 is formed by sticking the material 1 to the surface of the wall 3 in the vertical and horizontal directions. Then a switch cover or plug-socket cover is removed and the supply duct 7 of a hot air blower 6 is connected to the removed spot by using the spot as a blowing-in port 5. Then the temperature of the hot air blown from the blower 6 is set and the part of concrete where a conduit pipe is laid is warmed by blowing the hot air through the conduit pipe for a prescribed period of time. When the color of the material 1 which changes in color when the temperature of the material 1 reaches a prescribed value changes, the blower 6 is stopped and the color- changed portions 8 of the material 1 are recorded.
KOYAMA JUNJI
SAKURADA NAOKI
OEKI KEN
SAKUMA SHINJI
IHARA HIROKAZU
TSUMURA MASASHI
OKURA HISANORI
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